Abstract: A horizontal casting tray with one or more slidable blocks for sealing at least one open end of the tray is provided to accommodate the casting of solidifiable separation media in variable lengths for use in electrophoresis. Methods for using the casting device to prepare solidified medium having a concentration gradient are disclosed.

Abstract: A device for vertically stacking multiple pre-cast gels for simultaneous electrophoresis is described. The device comprises a plate of non-electrically conductive material that separates adjacent gels within a vertical stack and facilitates contact between the ends of the gels and an electrolyte solution during electrophoretic separation procedures. Further, a method of using the device for simultaneous electrophoresis of multiple pre-cast gels is disclosed.

Abstract: A plugging medium is used to block the bottom opening of cassettes for vertical electrophoresis in order to facilitate filling the cassettes with separation media. Cassettes can be filled within a vertical electrophoresis system in which electrophoresis is conducted without further manipulation of the cassettes. The system includes a frame assembly mounted on a base containing a basin for plugging solution. The cassette is mounted to the frame assembly in a substantially vertical position such that a bottom opening of the empty cassette resides below the rim of the basin. The plugging solution (e.g. agarose gel) forms a plug within the bottom of the cassette to contain the separation medium.